Call-routing apparatus, and associated method, for providing local call handling functions in a communication network

• US 20040114611A1
• Filed: 12/17/2002
• Published: 06/17/2004
• Est. Priority Date: 12/17/2002
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: OʼConnell, Pete, Chen, Xing, Hanson, Gary, Mani, Babu, Abraira, John
• Granted Patent: US 7,388,868 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04M 2242/04 for emergency applications
• CPC Class Codes: H04M 3/08 Indicating faults in circuits or apparatus
• CPC Class Codes: H04Q 2213/13166 Fault prevention
• CPC Class Codes: H04Q 2213/13196 Connection circuit/link/trunk/junction, bridge, router, gateway
• CPC Class Codes: H04Q 2213/1325 Priority service
• CPC Class Codes: H04Q 2213/13298 Local loop systems, access network
• CPC Class Codes: H04Q 2213/1337 Operator, emergency services
• CPC Class Codes: H04Q 2213/13389 LAN, internet
• CPC Class Codes: H04Q 3/66 Traffic distributors

Abstract

Emergency call-routing apparatus, and an associated method, for use in a packet-based, telephonic network. An emergency call router is positioned selectably to provide local call handling functionality to a local network that is normally connected by way of an access gateway to the telephonic network whose operation is normally controlled by a softswitch. The apparatus is used when, e.g., a total communication link failure condition occurs between the access gateway and the softswitch. The emergency call router selectably routes calls within the local network to permit continued, local calling functionality in spite of the failure of the communication link. High-priority calls, such as calls placed to an emergency dispatch center, are routed within the local network to a designated, local-network station. And local calls are also selectably routed by the emergency call router. A call priority scheme is also used in the event that call capacity is exceeded. Calls of higher priority are permitted while calls of lower priority are blocked.

Claims

1. In a communication system having a communication network, the communication system controlled by a communication system controller also connected to the communication network, and to an originating station operable to originate a call of at least a first selected call-type therefrom, the call routable by way of a normal-operation communication link, an improvement of apparatus for facilitating call completion of the call when the call is of the at least the first selected call-type and subsequent to failure of the normal-operation communication link, said apparatus comprising:

an emergency call router at least coupled to the access gateway, said emergency call router selectably operable responsive to failure of the normal-operation communication link for routing the call of the first selected call-type, thereby to facilitate call completion of the first selected call-type originated by the origination station.

2. The apparatus of claim 1 wherein the communication network further is coupled to at least a first access gateway and wherein said emergency call router is embodied at the first access gateway.

3. The apparatus of claim 1 wherein the communication network is further coupled to at least a first access gateway and wherein said emergency call router forms a standalone entity, connectable to the access gateway.

4. The apparatus of claim 1 wherein the communication network is further coupled to at least a first access gateway and wherein the access gateway comprises a functional aggregation point at which a first gateway device and at least a second gateway device are connected and wherein said emergency call router is coupled to the functional aggregation point.

5. The apparatus of claim 1 further comprising a detector coupled to receive indications of communication integrity on the normal-operation communication link, said detector for detecting failure of the normal-operation communication link.

6. The apparatus of claim 5 wherein the communication network is further coupled to at least a first access gateway and wherein said detector is embodied at the access gateway, said detector further for notifying said emergency call router of detection thereat of the failure of the normal-operation communication link.

7. The apparatus of claim 1 wherein the communication network is further coupled to at least a first access gateway and wherein said emergency call router further comprises a call priority determiner operable at least responsive to failure of the normal-operation communication link, said priority determiner for determining a priority level associated with the call of the at least the first selected call-type pursuant to a priority hierarchy.

8. The apparatus of claim 7 wherein the call comprises a call priority indicia and wherein said call priority determiner determines the priority level associated with the call responsive to the call priority indicia.

9. The apparatus of claim 8 wherein said emergency call router further comprises a priority sequence list containing a listing of at least relative call-priority types and wherein said emergency call router further comprises a priority-level comparator coupled to receive indications of the priority level associated with the call request and indications of the priority sequence list, said priority-level comparator for comparing the priority level associated with the call of the at least the first selected call-type with the call-priority types contained in the listing.

10. The apparatus of claim 9 wherein the communication system further comprises a public safety answering point coupled to the communication network, wherein the call of the first call-type comprises public-safety-answering-point-directed call, and wherein said emergency call router operates to route the public-safety-answering-point directed call.

11. The apparatus of claim 10 wherein the communication system further comprises a local-network alternate station coupled to an access gateway and wherein said emergency call router operates to route the public-service-access-point-directed call to the local-network alternate station.

12. The apparatus of claim 1 wherein the communication system further comprises a local-network alternate station, wherein said emergency call router is further for determining whether the call of the selected call-type shall be completable by way of the normal-operation communication link and for rerouting the call request to the local-network alternate station upon determination that the call completion by way of the normal-operation communication link.

13. The apparatus of claim 1 wherein the communication system further comprises a local network having at least a first local-network station, the local network associated with an access gateway, and wherein said emergency call router is further selectably operable responsive to failure of the normal-operation communication link for routing the call request to the local-network station.

14. The apparatus of claim 13 wherein the call request comprises a request for call termination at a selected one of the at least the first local-network station.

15. The apparatus of claim 14 wherein said emergency call router selects to route the call request to the local network station responsive to detection of the call and responsive to levels of call routing of the selected call-type.

16. The apparatus of claim 1 wherein said emergency call router comprises a portable standalone entity, deployable on an as-needed basis.

17. The apparatus of claim 16 wherein said emergency call router comprises a selectable database.

18. In a method of communicating in a communication system having a communication network, the communication system controlled by a communication system controller also connected to the communication network, and to an originating station operable to originate a call of at least a first selected call-type therefrom, the call routable by way of a normal-operation communication link, an improvement of a method for facilitating call completion of the call when the call is of the at least the first selected call-type and subsequent to failure of the normal-operation communication link, said method comprising:

detecting failure of the normal-operation communication link;

selectably routing a call request of the selected call-type by way of an emergency call router, thereby to facilitate call-completion of the selected call-type between the origination station and the terminating station.

19. The method of claim 18 wherein the communication system further comprises at least a first access gateway and a target gateway and wherein said method further comprises the preliminary operation of connecting the emergency call router between the access gateway and the target gateway.

20. The method of claim 19 further comprising the operation, prior to said operation of selectably routing, of determining whether the call request is for a call of the selected call-type.